In a typical grass cutter, a structure is employed in which a rotary blade is positioned between a blade rest sleeve that rotates together with a drive shaft around the outer periphery of a rotating drive shaft and a blade retaining plate installed on the end of the drive shaft, and the rotary blade is attached by clamping the rotary blade between the blade rest sleeve and the blade retaining plate by tightening a nut. A grass cutter disclosed in Japanese Patent Application Laid-open No. H9-172840 teaches that grass cutting work can be carried out comfortably by attaching a ground surface slide guide to the lower surface side of a rotary blade and allowing this ground surface slide guide to contact the surface of the ground during grass cutting. In addition, since this ground surface slide guide is provided in the form of a metal-made article making it heavy, only a small such slide guide can be used in consideration of workability, thereby resulting in the problem of having insufficient stability with respect to the surface of the ground. Moreover, since this ground surface slide guide is formed by pressing a single metal sheet, the thickness of the location that contacts the ground is the same as that of other locations, thereby resulting in the problem of the location that contacts the ground becoming worn as a result of use and failing comparatively at a comparatively early stage of its service life.